NEW YORK — Individuals at average risk for colon cancer should be screened for the disease beginning at age 45, five years earlier than previously recommended, the US Preventive Services Task Force said on Tuesday.
The guidance, which appeared in the Journal of the American Medical Association, updates the USPSTF's 2016 recommendation that average-risk people should be screened for colorectal cancer at ages 50 through 75. While the agency continues to recommend screening in that age group, a new modeling study indicated that the benefits of screening earlier with stool tests, endoscopy, or computer tomography colonography outweigh the burdens.
The USPSTF-commissioned study used three independently developed microsimulation models of colorectal cancer screening in a hypothetical cohort of 40-year-old US individuals at average risk for the disease. All three models had been used in developing the previous recommendations but were updated to include observed trends in the US population risk of colorectal cancer, which point to increased incidence of the disease among those under the age of 50.
All three models found that initiating colorectal cancer screening at age 45 provides an efficient balance of colonoscopy burden and life-years gained. Specifically, beginning screening five years sooner than previously recommended was projected to be associated with around 22 to 27 additional life-years gained versus starting at age 50, but with only a small increase in the number of complications.
Notably, the USPSTF also for the first time analyzed the impact of colorectal screening by race and sex for the two most commonly used screening methods — colonoscopy and fecal immunochemical testing — and found that starting screening at age 45 provided an efficient balance of benefits and burdens in all subgroups.
As in its 2016 guidelines, the USPSTF continues to recommend all adults aged 50 to 75 should undergo colorectal cancer screening, a recommendation it gave an A grade to indicate a high certainty of substantial net benefit. The recommendation for screening in average-risk people aged 45 to 49 received a B grade, indicating a high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial.
The USPSTF continues to recommend only selective colorectal cancer screening in people aged 76 to 85 based on evidence indicating that the net benefit of screening in this population is small.
In an accompanying JAMA editorial, Dana-Farber Cancer Institute's Kimmie Ng and Deborah Schrag, along with Folasade May from the University of California, Los Angeles, noted that the updated USPSTF guidelines come amid both a decline in the overall incidence of colorectal cancer and a "concerning increase" in incidence among younger individuals.
The recommendation for screening for average risk adults beginning at age 45 "has moved the field one step forward and … will make lifesaving colorectal cancer screening available to millions more people in the US and offer the potential for averting colorectal cancer diagnoses and deaths," they wrote. "However, the real work lies ahead in implementing the new recommendations, ensuring equitable access, and conducting research to elucidate the underlying causes of the increase in young-onset colorectal cancer."
In a research note, Leerink's Puneet Souda said the new guidelines would most benefit Exact Sciences in the near term. In September 2019, the US Food and Drug Administration expanded approval of the company's Cologuard test for use with average-risk individuals 45 and older, adding about 19 million patients to the overall population suitable or the test. Longer term, the change could be a positive for firms developing liquid biopsy-based screening tests such as Guardant Health, "as USPSTF recognizes a moderate impact of screening 45 to 49-year-olds for [colorectal cancer]. Recall, [Guardant Health's] ECLIPSE trial is enrolling 45-84 years of age average risk individuals," Souda said.